Technically a walnut is the seed of a drupe or drupaceous nut and thus not a true botanical nut. It is used for food after being processed, while green for pickled walnuts or after full ripening for its nutmeat. Nutmeat of the eastern black walnut from the Juglans nigra is less commercially available, as are butternut nutmeats from Juglans cinerea.
Walnut meats are available in two forms; in their shells or shelled. The meats may be whole, halved, or in smaller portions due to processing. Walnuts are often candied, and may be used as an ingredient in other foodstuffs. Pickled walnuts that are the whole fruit can be savory or sweet depending on the preserving solution. Walnut butters can be homemade or purchased in both raw and roasted forms. All walnuts can be eaten on their own (raw, toasted or pickled) or as part of a mix such as muesli, or as an ingredient of a dish. For example, walnut soup and walnut pie are prepared using walnuts as a main ingredient. Walnut Whip, coffee and walnut cake, and pickled walnuts are more examples.
Walnut is the main ingredient of Fesenjan, a khoresh (stew) in Iranian cuisine. Walnuts are also popular in brownie recipes, as ice cream toppings, and walnut pieces are used as a garnish on some foods. Nocino is a liqueur made from unripe green walnuts steeped in alcohol with syrup added.